/*
 * A fast javascript implementation of simplex noise by Jonas Wagner
 *
 * Based on a speed-improved simplex noise algorithm for 2D, 3D and 4D in Java.
 * Which is based on example code by Stefan Gustavson (stegu@itn.liu.se).
 * With Optimisations by Peter Eastman (peastman@drizzle.stanford.edu).
 * Better rank ordering method by Stefan Gustavson in 2012.
 *
 *
 * Copyright (C) 2016 Jonas Wagner
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */
(function () {
  const F2 = 0.5 * (Math.sqrt(3.0) - 1.0);
  const G2 = (3.0 - Math.sqrt(3.0)) / 6.0;
  const F3 = 1.0 / 3.0;
  const G3 = 1.0 / 6.0;
  const F4 = (Math.sqrt(5.0) - 1.0) / 4.0;
  const G4 = (5.0 - Math.sqrt(5.0)) / 20.0;

  function SimplexNoise(random) {
    if (!random) random = Math.random;
    this.p = buildPermutationTable(random);
    this.perm = new Uint8Array(512);
    this.permMod12 = new Uint8Array(512);
    for (let i = 0; i < 512; i++) {
      this.perm[i] = this.p[i & 255];
      this.permMod12[i] = this.perm[i] % 12;
    }
  }
  SimplexNoise.prototype = {
    grad3: new Float32Array([1, 1, 0,
      -1, 1, 0,
      1, -1, 0,

      -1, -1, 0,
      1, 0, 1,
      -1, 0, 1,

      1, 0, -1,
      -1, 0, -1,
      0, 1, 1,

      0, -1, 1,
      0, 1, -1,
      0, -1, -1]),
    grad4: new Float32Array([0, 1, 1, 1, 0, 1, 1, -1, 0, 1, -1, 1, 0, 1, -1, -1,
      0, -1, 1, 1, 0, -1, 1, -1, 0, -1, -1, 1, 0, -1, -1, -1,
      1, 0, 1, 1, 1, 0, 1, -1, 1, 0, -1, 1, 1, 0, -1, -1,
      -1, 0, 1, 1, -1, 0, 1, -1, -1, 0, -1, 1, -1, 0, -1, -1,
      1, 1, 0, 1, 1, 1, 0, -1, 1, -1, 0, 1, 1, -1, 0, -1,
      -1, 1, 0, 1, -1, 1, 0, -1, -1, -1, 0, 1, -1, -1, 0, -1,
      1, 1, 1, 0, 1, 1, -1, 0, 1, -1, 1, 0, 1, -1, -1, 0,
      -1, 1, 1, 0, -1, 1, -1, 0, -1, -1, 1, 0, -1, -1, -1, 0]),
    noise2D(xin, yin) {
      const { permMod12 } = this;
      const { perm } = this;
      const { grad3 } = this;
      let n0 = 0; // Noise contributions from the three corners
      let n1 = 0;
      let n2 = 0;
      // Skew the input space to determine which simplex cell we're in
      const s = (xin + yin) * F2; // Hairy factor for 2D
      const i = Math.floor(xin + s);
      const j = Math.floor(yin + s);
      const t = (i + j) * G2;
      const X0 = i - t; // Unskew the cell origin back to (x,y) space
      const Y0 = j - t;
      const x0 = xin - X0; // The x,y distances from the cell origin
      const y0 = yin - Y0;
      // For the 2D case, the simplex shape is an equilateral triangle.
      // Determine which simplex we are in.
      let i1; let
        j1; // Offsets for second (middle) corner of simplex in (i,j) coords
      if (x0 > y0) {
        i1 = 1;
        j1 = 0;
      } // lower triangle, XY order: (0,0)->(1,0)->(1,1)
      else {
        i1 = 0;
        j1 = 1;
      } // upper triangle, YX order: (0,0)->(0,1)->(1,1)
      // A step of (1,0) in (i,j) means a step of (1-c,-c) in (x,y), and
      // a step of (0,1) in (i,j) means a step of (-c,1-c) in (x,y), where
      // c = (3-sqrt(3))/6
      const x1 = x0 - i1 + G2; // Offsets for middle corner in (x,y) unskewed coords
      const y1 = y0 - j1 + G2;
      const x2 = x0 - 1.0 + 2.0 * G2; // Offsets for last corner in (x,y) unskewed coords
      const y2 = y0 - 1.0 + 2.0 * G2;
      // Work out the hashed gradient indices of the three simplex corners
      const ii = i & 255;
      const jj = j & 255;
      // Calculate the contribution from the three corners
      let t0 = 0.5 - x0 * x0 - y0 * y0;
      if (t0 >= 0) {
        const gi0 = permMod12[ii + perm[jj]] * 3;
        t0 *= t0;
        n0 = t0 * t0 * (grad3[gi0] * x0 + grad3[gi0 + 1] * y0); // (x,y) of grad3 used for 2D gradient
      }
      let t1 = 0.5 - x1 * x1 - y1 * y1;
      if (t1 >= 0) {
        const gi1 = permMod12[ii + i1 + perm[jj + j1]] * 3;
        t1 *= t1;
        n1 = t1 * t1 * (grad3[gi1] * x1 + grad3[gi1 + 1] * y1);
      }
      let t2 = 0.5 - x2 * x2 - y2 * y2;
      if (t2 >= 0) {
        const gi2 = permMod12[ii + 1 + perm[jj + 1]] * 3;
        t2 *= t2;
        n2 = t2 * t2 * (grad3[gi2] * x2 + grad3[gi2 + 1] * y2);
      }
      // Add contributions from each corner to get the final noise value.
      // The result is scaled to return values in the interval [-1,1].
      return 70.0 * (n0 + n1 + n2);
    },
    // 3D simplex noise
    noise3D(xin, yin, zin) {
      const { permMod12 } = this;
      const { perm } = this;
      const { grad3 } = this;
      let n0; let n1; let n2; let
        n3; // Noise contributions from the four corners
        // Skew the input space to determine which simplex cell we're in
      const s = (xin + yin + zin) * F3; // Very nice and simple skew factor for 3D
      const i = Math.floor(xin + s);
      const j = Math.floor(yin + s);
      const k = Math.floor(zin + s);
      const t = (i + j + k) * G3;
      const X0 = i - t; // Unskew the cell origin back to (x,y,z) space
      const Y0 = j - t;
      const Z0 = k - t;
      const x0 = xin - X0; // The x,y,z distances from the cell origin
      const y0 = yin - Y0;
      const z0 = zin - Z0;
      // For the 3D case, the simplex shape is a slightly irregular tetrahedron.
      // Determine which simplex we are in.
      let i1; let j1; let
        k1; // Offsets for second corner of simplex in (i,j,k) coords
      let i2; let j2; let
        k2; // Offsets for third corner of simplex in (i,j,k) coords
      if (x0 >= y0) {
        if (y0 >= z0) {
          i1 = 1;
          j1 = 0;
          k1 = 0;
          i2 = 1;
          j2 = 1;
          k2 = 0;
        } // X Y Z order
        else if (x0 >= z0) {
          i1 = 1;
          j1 = 0;
          k1 = 0;
          i2 = 1;
          j2 = 0;
          k2 = 1;
        } // X Z Y order
        else {
          i1 = 0;
          j1 = 0;
          k1 = 1;
          i2 = 1;
          j2 = 0;
          k2 = 1;
        } // Z X Y order
      } else { // x0<y0
        if (y0 < z0) {
          i1 = 0;
          j1 = 0;
          k1 = 1;
          i2 = 0;
          j2 = 1;
          k2 = 1;
        } // Z Y X order
        else if (x0 < z0) {
          i1 = 0;
          j1 = 1;
          k1 = 0;
          i2 = 0;
          j2 = 1;
          k2 = 1;
        } // Y Z X order
        else {
          i1 = 0;
          j1 = 1;
          k1 = 0;
          i2 = 1;
          j2 = 1;
          k2 = 0;
        } // Y X Z order
      }
      // A step of (1,0,0) in (i,j,k) means a step of (1-c,-c,-c) in (x,y,z),
      // a step of (0,1,0) in (i,j,k) means a step of (-c,1-c,-c) in (x,y,z), and
      // a step of (0,0,1) in (i,j,k) means a step of (-c,-c,1-c) in (x,y,z), where
      // c = 1/6.
      const x1 = x0 - i1 + G3; // Offsets for second corner in (x,y,z) coords
      const y1 = y0 - j1 + G3;
      const z1 = z0 - k1 + G3;
      const x2 = x0 - i2 + 2.0 * G3; // Offsets for third corner in (x,y,z) coords
      const y2 = y0 - j2 + 2.0 * G3;
      const z2 = z0 - k2 + 2.0 * G3;
      const x3 = x0 - 1.0 + 3.0 * G3; // Offsets for last corner in (x,y,z) coords
      const y3 = y0 - 1.0 + 3.0 * G3;
      const z3 = z0 - 1.0 + 3.0 * G3;
      // Work out the hashed gradient indices of the four simplex corners
      const ii = i & 255;
      const jj = j & 255;
      const kk = k & 255;
      // Calculate the contribution from the four corners
      let t0 = 0.6 - x0 * x0 - y0 * y0 - z0 * z0;
      if (t0 < 0) n0 = 0.0;
      else {
        const gi0 = permMod12[ii + perm[jj + perm[kk]]] * 3;
        t0 *= t0;
        n0 = t0 * t0 * (grad3[gi0] * x0 + grad3[gi0 + 1] * y0 + grad3[gi0 + 2] * z0);
      }
      let t1 = 0.6 - x1 * x1 - y1 * y1 - z1 * z1;
      if (t1 < 0) n1 = 0.0;
      else {
        const gi1 = permMod12[ii + i1 + perm[jj + j1 + perm[kk + k1]]] * 3;
        t1 *= t1;
        n1 = t1 * t1 * (grad3[gi1] * x1 + grad3[gi1 + 1] * y1 + grad3[gi1 + 2] * z1);
      }
      let t2 = 0.6 - x2 * x2 - y2 * y2 - z2 * z2;
      if (t2 < 0) n2 = 0.0;
      else {
        const gi2 = permMod12[ii + i2 + perm[jj + j2 + perm[kk + k2]]] * 3;
        t2 *= t2;
        n2 = t2 * t2 * (grad3[gi2] * x2 + grad3[gi2 + 1] * y2 + grad3[gi2 + 2] * z2);
      }
      let t3 = 0.6 - x3 * x3 - y3 * y3 - z3 * z3;
      if (t3 < 0) n3 = 0.0;
      else {
        const gi3 = permMod12[ii + 1 + perm[jj + 1 + perm[kk + 1]]] * 3;
        t3 *= t3;
        n3 = t3 * t3 * (grad3[gi3] * x3 + grad3[gi3 + 1] * y3 + grad3[gi3 + 2] * z3);
      }
      // Add contributions from each corner to get the final noise value.
      // The result is scaled to stay just inside [-1,1]
      return 32.0 * (n0 + n1 + n2 + n3);
    },
    // 4D simplex noise, better simplex rank ordering method 2012-03-09
    noise4D(x, y, z, w) {
      const { permMod12 } = this;
      const { perm } = this;
      const { grad4 } = this;

      let n0; let n1; let n2; let n3; let
        n4; // Noise contributions from the five corners
        // Skew the (x,y,z,w) space to determine which cell of 24 simplices we're in
      const s = (x + y + z + w) * F4; // Factor for 4D skewing
      const i = Math.floor(x + s);
      const j = Math.floor(y + s);
      const k = Math.floor(z + s);
      const l = Math.floor(w + s);
      const t = (i + j + k + l) * G4; // Factor for 4D unskewing
      const X0 = i - t; // Unskew the cell origin back to (x,y,z,w) space
      const Y0 = j - t;
      const Z0 = k - t;
      const W0 = l - t;
      const x0 = x - X0; // The x,y,z,w distances from the cell origin
      const y0 = y - Y0;
      const z0 = z - Z0;
      const w0 = w - W0;
      // For the 4D case, the simplex is a 4D shape I won't even try to describe.
      // To find out which of the 24 possible simplices we're in, we need to
      // determine the magnitude ordering of x0, y0, z0 and w0.
      // Six pair-wise comparisons are performed between each possible pair
      // of the four coordinates, and the results are used to rank the numbers.
      let rankx = 0;
      let ranky = 0;
      let rankz = 0;
      let rankw = 0;
      if (x0 > y0) rankx++;
      else ranky++;
      if (x0 > z0) rankx++;
      else rankz++;
      if (x0 > w0) rankx++;
      else rankw++;
      if (y0 > z0) ranky++;
      else rankz++;
      if (y0 > w0) ranky++;
      else rankw++;
      if (z0 > w0) rankz++;
      else rankw++;
      let i1; let j1; let k1; let
        l1; // The integer offsets for the second simplex corner
      let i2; let j2; let k2; let
        l2; // The integer offsets for the third simplex corner
      let i3; let j3; let k3; let
        l3; // The integer offsets for the fourth simplex corner
        // simplex[c] is a 4-vector with the numbers 0, 1, 2 and 3 in some order.
        // Many values of c will never occur, since e.g. x>y>z>w makes x<z, y<w and x<w
        // impossible. Only the 24 indices which have non-zero entries make any sense.
        // We use a thresholding to set the coordinates in turn from the largest magnitude.
        // Rank 3 denotes the largest coordinate.
      i1 = rankx >= 3 ? 1 : 0;
      j1 = ranky >= 3 ? 1 : 0;
      k1 = rankz >= 3 ? 1 : 0;
      l1 = rankw >= 3 ? 1 : 0;
      // Rank 2 denotes the second largest coordinate.
      i2 = rankx >= 2 ? 1 : 0;
      j2 = ranky >= 2 ? 1 : 0;
      k2 = rankz >= 2 ? 1 : 0;
      l2 = rankw >= 2 ? 1 : 0;
      // Rank 1 denotes the second smallest coordinate.
      i3 = rankx >= 1 ? 1 : 0;
      j3 = ranky >= 1 ? 1 : 0;
      k3 = rankz >= 1 ? 1 : 0;
      l3 = rankw >= 1 ? 1 : 0;
      // The fifth corner has all coordinate offsets = 1, so no need to compute that.
      const x1 = x0 - i1 + G4; // Offsets for second corner in (x,y,z,w) coords
      const y1 = y0 - j1 + G4;
      const z1 = z0 - k1 + G4;
      const w1 = w0 - l1 + G4;
      const x2 = x0 - i2 + 2.0 * G4; // Offsets for third corner in (x,y,z,w) coords
      const y2 = y0 - j2 + 2.0 * G4;
      const z2 = z0 - k2 + 2.0 * G4;
      const w2 = w0 - l2 + 2.0 * G4;
      const x3 = x0 - i3 + 3.0 * G4; // Offsets for fourth corner in (x,y,z,w) coords
      const y3 = y0 - j3 + 3.0 * G4;
      const z3 = z0 - k3 + 3.0 * G4;
      const w3 = w0 - l3 + 3.0 * G4;
      const x4 = x0 - 1.0 + 4.0 * G4; // Offsets for last corner in (x,y,z,w) coords
      const y4 = y0 - 1.0 + 4.0 * G4;
      const z4 = z0 - 1.0 + 4.0 * G4;
      const w4 = w0 - 1.0 + 4.0 * G4;
      // Work out the hashed gradient indices of the five simplex corners
      const ii = i & 255;
      const jj = j & 255;
      const kk = k & 255;
      const ll = l & 255;
      // Calculate the contribution from the five corners
      let t0 = 0.6 - x0 * x0 - y0 * y0 - z0 * z0 - w0 * w0;
      if (t0 < 0) n0 = 0.0;
      else {
        const gi0 = (perm[ii + perm[jj + perm[kk + perm[ll]]]] % 32) * 4;
        t0 *= t0;
        n0 = t0 * t0 * (grad4[gi0] * x0 + grad4[gi0 + 1] * y0 + grad4[gi0 + 2] * z0 + grad4[gi0 + 3] * w0);
      }
      let t1 = 0.6 - x1 * x1 - y1 * y1 - z1 * z1 - w1 * w1;
      if (t1 < 0) n1 = 0.0;
      else {
        const gi1 = (perm[ii + i1 + perm[jj + j1 + perm[kk + k1 + perm[ll + l1]]]] % 32) * 4;
        t1 *= t1;
        n1 = t1 * t1 * (grad4[gi1] * x1 + grad4[gi1 + 1] * y1 + grad4[gi1 + 2] * z1 + grad4[gi1 + 3] * w1);
      }
      let t2 = 0.6 - x2 * x2 - y2 * y2 - z2 * z2 - w2 * w2;
      if (t2 < 0) n2 = 0.0;
      else {
        const gi2 = (perm[ii + i2 + perm[jj + j2 + perm[kk + k2 + perm[ll + l2]]]] % 32) * 4;
        t2 *= t2;
        n2 = t2 * t2 * (grad4[gi2] * x2 + grad4[gi2 + 1] * y2 + grad4[gi2 + 2] * z2 + grad4[gi2 + 3] * w2);
      }
      let t3 = 0.6 - x3 * x3 - y3 * y3 - z3 * z3 - w3 * w3;
      if (t3 < 0) n3 = 0.0;
      else {
        const gi3 = (perm[ii + i3 + perm[jj + j3 + perm[kk + k3 + perm[ll + l3]]]] % 32) * 4;
        t3 *= t3;
        n3 = t3 * t3 * (grad4[gi3] * x3 + grad4[gi3 + 1] * y3 + grad4[gi3 + 2] * z3 + grad4[gi3 + 3] * w3);
      }
      let t4 = 0.6 - x4 * x4 - y4 * y4 - z4 * z4 - w4 * w4;
      if (t4 < 0) n4 = 0.0;
      else {
        const gi4 = (perm[ii + 1 + perm[jj + 1 + perm[kk + 1 + perm[ll + 1]]]] % 32) * 4;
        t4 *= t4;
        n4 = t4 * t4 * (grad4[gi4] * x4 + grad4[gi4 + 1] * y4 + grad4[gi4 + 2] * z4 + grad4[gi4 + 3] * w4);
      }
      // Sum up and scale the result to cover the range [-1,1]
      return 27.0 * (n0 + n1 + n2 + n3 + n4);
    },
  };

  function buildPermutationTable(random) {
    let i;
    const p = new Uint8Array(256);
    for (i = 0; i < 256; i++) {
      p[i] = i;
    }
    for (i = 0; i < 255; i++) {
      const r = i + ~~(random() * (256 - i));
      const aux = p[i];
      p[i] = p[r];
      p[r] = aux;
    }
    return p;
  }
  SimplexNoise._buildPermutationTable = buildPermutationTable;

  // amd
  if (typeof define !== 'undefined' && define.amd) define(() => SimplexNoise);
  // common js
  if (typeof exports !== 'undefined') exports.SimplexNoise = SimplexNoise;
  // browser
  else if (typeof window !== 'undefined') window.SimplexNoise = SimplexNoise;
  // nodejs
  if (typeof module !== 'undefined') {
    module.exports = SimplexNoise;
  }
}());
